Healthy aging is characterized by declines in language function and it is important to differentiate language comprehension difficulties due to pathological aging (i.e., mild cognitive impairment) from those due to normal aging. The purposes of this study were to review the literature on characteristics of language comprehension in normal elderly and the mild cognitive impaired, and to compare their performances on different language domains.

A comprehensive literature search identified numerous studies on language comprehension in both groups, and we analyzed them according to each language domain.

The results indicated that the normal elderly show more difficulties in the comprehension of grammatically or lexically complex sentences and in text/discourse comprehension than words or simple sentences. Compared to normal elderly, MCI shows significantly lower performance on text/discourse comprehension and other tasks demanding higher cognitive function. In both groups, there are many different factors affecting language comprehension, such as hearing sensitivity, speech rate, literacy, and cognition.

The results may provide insight into useful language comprehension tasks for differential diagnosis between normal aging and MCI. Further research on various compensatory strategies in daily life to facilitate language comprehension for both groups is warranted.